Earth System History by Steven M. Stanley

Understanding Earth Science and Climate Change

In understanding climate change issues we must rely on the past to "try" to predict the future. That means we study that boring old earth science. If one is too lazy and desires blind faith in "experts" then go visit the Disney website.

I reject computer modeling as speculation unless it matches past events. Greener as in more plant growth meaning more animal life is better. Humans are animal life that takes precedence over nature. If one can't accept that go visit the Disney website.

If one is serious then learn something for yourself. I claim no magical expertise on this subject other than lifelong study and a general college science background. I can't predict the future nor can the "experts". I have tried to present this material in more laymen's terms.

Geology is based on the concept of actualism. Science says processes of the past are the same processes of today. If the process worked in the past, it will work today and in the future. But they may not be exactly the same outcome because the earth differs from the past. The "process" may proceed at a differing rate.

We may understand a geological or chemical process, that doesn't mean we can know outcome. Meteor strikes like that that killed the dinosaurs can't be predicted. Cosmic rays that interact with the atmosphere to change climate can't be predicted. Solar output varies and is difficult to completely predict.

Random events such as these have what I call a snowball effect - a little snowball roles down the geological hill, get deflected, can result in an unknown size big snowball landing on an unknown geological sky resort. Continental drift in the past was far faster than today because the earth's core was hotter. Volcanism was greater in the past.

Homeostasis and hysteresis can both delay change and resist change. These are often unknown and complicating factors in earth's geology. Deep oceans for example are still cold from the Little Ice Age that ended 200 years ago. They are reported warming it back up and it should be.

Trying to compare human activity to the End Permian Extinction is asinine. To pretend humans can control nature is like a saber-tooth cat taking on a mouse - we are that yummy mouse.

Nature is not static. Nature does not proceed on a straight and narrow track. Nature is cyclical. It has bumps, turns, and dead ends. Many events from our viewpoint are random. The sooner we learn that and plan for change the better.

Summary: In the geological past the earth was warmer, wetter, and far greener than today. CO2 levels were higher due to warmer climate driven by water vapor and CO2. Antarctica glaciers caused lower temperatures, drying, dropping CO2 levels, and mass forest die off.

Continued cooling and drying 6-7 MYA led to the extinctions of many large mammals with changes in plant types.

In the geological sense we are in the Phanerozioc Eon (542 MYA), Cenozoic Era (65.5 MYA), the Neogene Period (23 MYA) and the modern Holocene Epoch that goes back 11,700 years.

The Neogene that followed the death of the dinosaurs is important to understand present climate.

I know that is confusing so bear with me. During the Holocene climate has varied dramatically in as little as a few years.

What about extreme greenhouse cooling and warming? Negative feedbacks hold CO2 levels in check:

"In fact, neither drastic heating nor drastic cooling of the Earth's climate appears to have been possible in the Phanerozioc world." (Last 542 million years.)

This is based on four interlocking factors of CO2, temperature, plant growth, and weathering of rocks. I'll also add continental drift into the mix. Keeping it simple:

Warmer temperatures - more water evaporation thus precipitation or rain. The rain has dissolved CO2 forming a weak acid. Moisture promotes huge increases in plant growth taking up more CO2. The rain and decaying plant matter (including expanding forests) combine to erode-weather rocks, etc.

This releases calcium, magnesium, etc. that flow into the oceans from rivers and streams. This forms carbonate rocks (limestone, chalk, sea shells, etc.) and carbonate sludge locking away CO2 on the ocean floor.

As Dr. Stanley notes this prevents a "runaway greenhouse effect" environmental activists like to claim. Climate change won't make the earth like Venus. Stanley P230-32.

Phanerozioc Eon 542 MYA begins at Cambrian to today. The fossil record shows an "explosion" of complex life forms.

Cenozoic Era 65.5 million years ago to today. (MYA) Known as the Age of Mammals, flowering plants, and for the last 34 million years global cooling. A great deal of mountain building has also taken place.

Paleogene Period 65.5 - 23 MYA. includes the following:

Paleocene Epoch 65.5 - 56 MYA.

Eocene Epoch 56 - 34 MYA. 42 MYA CO2 levels were over 2000 PPM about 10 times the level of today. Stanley P442. Water cycling between rain, soil, and forests keeps climate very warm.

Oligocene Epoch 34 - 23 MYA. Global cooling and drying begins with Antarctica circumpolar current at 34 MYA. Most forests die out. Glacier expansion in Antarctica changed world climate sucking up vast amounts of moisture and cooling deep oceans.

Neogene Period 23 MYA to present. Includes the following:

Miocene Epoch 23 - 5.3 MYA. CO2 levels increased from ~200 PPM to 320 PPM. During this time continued cooling and drying. Forests continue to decline, deserts and grasslands expand. That likely led to some rebound in CO2 levels.

Pliocene Epoch 5.3 - 1.8 MYA. Early Pliocene was warm. Winters were warmer, England was subtropical. Modern ice ages began ~3.2 million years ago. By 2.6 MYA the Arctic sea froze over for the first time. Temperatures plummeted even with higher CO2 levels.

Pleistocene Epoch 1.8 - 11,700 MYA. Mostly an ice age. Sea level 400 feet lower, many forests die out.

Holocene Epoch 11,700 years ago to today. Chesapeake river valley flooded to form Chesapeake Bay. Last continental glacier outside Greenland melted in 4000BC. Greenland has the only continental glaciers in the Northern Hemisphere today. Global warming has been ongoing for 20,000 years with periods of interruption, some sudden. Stanley P461.

Hyper-warming between 9000 to 6000 years ago allowed agriculture to spread to Europe. Sudden sea level rise kills shallow water corals in Florida and Caribbean ~7600 years ago.

Sea ice melt has opened the Northwest Passage from Atlantic to Pacific three times so far in the Holocene. This is according to whale bone fossil studies.

Medieval Warm Period 900 - 1300. Greenland settled by Vikings. Little Ice Age 1300 - ~1850. Mountain glaciers and sea ice expanded. Greenland colony died out by ~1400.

Modern warming began in 1800. Those mountain glaciers began warming and are still melting today. The rate of melt should have accelerated over time if the climate stayed warmer, which it did.

Homeostasis and hysteresis come into play again as mass mountain glacier melting didn't begin at 1800. Enough heat built up over time to produce the accelerated melting we see today. Remember my snowball analogy - a slow snowball at first.